Módulo 4: Básico de Lan

Transcrição

1 Módulo 4: Básico de Lan

2 Agenda Ethernet Token Ring FDDI

3 Tecnologias mais comuns em Lans Ethernet Token Ring Token Ring FDDI FDDI Dual Ring

4 Ethernet

5 Ethernet - IEEE Benefícios Ethernet é a mais popular tecnologia de LAN porque encontra uma boa performance entre velocidade, custo e facilidade de instalação. Suporta teóricamente todos os protocolos de rede. Instituída pela Xerox, quando da junção entre DEC & Intel em 1980 Revisões das Especificações da Ethernet Fast Ethernet (IEEE 802.3u) aumento de velocidade de 10 Mbps para 100 Mbps Gigabit Ethernet é uma extensão do IEEE que aumenta a velocidades para 1000 Mbps, ou 1 Gbps

6 Ethernet - IEEE Diversas variações de frames são encontradas nesta tecnologia de LAN, fato que não atrapalha o desenvolvimento dos cartões de rede pelos inúmeros fabricantes.

7 Ethernet Protocol Names 100Base5 Velocidade da LAN ( bps ) Indica o tipo do cabo E o seu tamanho máximo. Tamanho max. = # x 100 m Ex. 10base5 => 5 x 100 = 500m Base = baseband Broad = broadband

8 Ethernet e Fast Ethernet Protocol Max. Segment Length (m) Transmission Medium Application 10Base ohm coaxial A: Link user stations 10Base ohm coaxial A: Link user stations 10BaseF Refers to 10BaseFB, 10BaseFL, and 10Base FP 10BaseFB 2000 Fiber-optic A: Add segments 10BaseFL Fiber-optic A: Operate w/ FOIRL 10BaseFP 500 Fiber-optic Star topo w/out repeaters 10BaseT pairs TP Sends link signals 10Broad Broadband coax A: Broadband 100BaseFX strands of multimode fiber-optic cable 100BaseT 100 UTP 10BaseT function + more 100BaseT prs Cat 3-5 UTP - 100BaseTX prs UTP or STP - 100BaseX Refers to 2 strand/pair 100BaseFX and 100BaseTX

9 O Funcionamento da Ethernet A B C D

10 O Funcionamento da Ethernet A B C D D Application Presentation Session Transport Network Data Link Physical

11 O Funcionamento da Ethernet A B C D D Application Presentation Session Transport Network Data Link Physical B and C Application Presentation Session Transport Network Data Link Physical

12 Ethernet Broadcast A Application Presentation Session Transport Network Data Link Physical B Application Presentation Session Transport Network Data Link Physical C Application Presentation Session Transport Network Data Link Physical D Application Presentation Session Transport Network Data Link Physical

13 A Confiabilidade da Ethernet Figura 1 A B C D Figura 2 A B C D Colisão

14 Ethernet Reliability A B C D Colisão A B C D JAM JAM JAM JAM JAM JAM

15 Ethernet Reliability A B C D A Collision B C D JAM JAM JAM JAM JAM Carrier sense multiple access with collision detection (CSMA/CD) JAM

16 As opções de Alta Velocidade da Ethernet Fast Ethernet Fast EtherChannel Gigabit Ethernet Gigabit EtherChannel

17 O que é Fast EtherChannel? Grupo de múltiplas m interfaces Fast Ethernet operando como uma única porta lógica. l 800 Mb 800 Mb 600 Mb 400 Mb Largura de banda crescente até 800+ Mbps Customizado em padrões da Fast Ethernet Balanceamento de carga através de links paralelos Extensiva para Gigabit Ethernet

18 O que é Gigabit Ethernet? 1000-Mbps data rate 802.3/Ethernet frames Full duplex or half duplex Meios de acesso em Fibra ou cabo 100% compatível com os já existentes: Protocolos de rede Sistemas Operacionais de Rede Aplicações de Redes Gerenciamento de Rede 20% 80% Workgroup 80% Backbone 20%

19 Token Ring

20 Token Ring (IEEE 802.5) História Desenvolvida pela IBM nos anos 70; IEEE tem especificações totalmente compatíveis com o Token Ring Segundo padrão mais popular, perdendo apenas para a Ethernet. Características Token determines transmission so no collisions Ideal for applications (such as factory automation) where delay must be predictable and robust network operation is important More difficult and costly than Ethernet, but little impact as more users are added to system

21 Token Ring IBM Token Token Ring Ring Network IEEE Data Rates 4 or 16 Mbps 4 or 16 Mbps Stations/Seg 260 STP, 72 UTP 250 Topology Star Not specified Media Twisted-pair Not specified Signaling Baseband Baseband

22 Topologia Token Ring MAU Shielded or Unshielded Twisted-Pair Logicamente opera como um anel, mas fisicamente opera em configuração estrela com a utilização do MAU ( Multistation access unit ).

23 Token Ring Operation T A T = 0 Token Ring LANs continuously pass a token or a Token Ring frame

24 Token Ring Operation T A T = 0 A T = 1 T Data Token Ring LANs continuously pass a token or a Token Ring frame

25 Token Ring Operation T A T = 0 A T = 0 T A T = 1 T Data Token Ring LANs continuously pass a token or a Token Ring frame

26 Token Ring Summary Reliable transport, minimized collisions Token passing/token seizing 4- or 16-Mbps transport Little performance impact with increased number of users Popular at IBM-oriented sites such as banks and automated factories

27 FDDI 1999, Cisco Systems, Inc.

28 Fiber Distributed Data Interface (FDDI) Fiber Distributed Data Interface (FDDI) Defined by ANSI X3T9.5 spec in mid 1980s 100-Mbps tokenpassing network 100 Mbps Fiber-optic cable with FDDI max. distance of 2 km Dual Ring Dual-ring architecture for redundancy Used for corporate and carrier backbones CDDI Implements FDDI over STP and UTP cable Transmits at 100 Mbps over about 100 m

29 FDDI Network Architecture Dual-ring architecture Primary ring for data transmissions Secondary ring for reliability and robustness Components Single attachment station (SAS) PCs Dual attachment station (DAS) Servers Concentrator FDDI concentrator Also called a dual-attached concentrator (DAC) Building block of an FDDI network Attaches directly to both rings and ensures that any SAS failure or power-down does not bring down the ring

30 FDDI Network Example Primary Ring DAS Secondary Ring FDDI Concentrator DAS WAN SAS SAS

31 FDDI Summary Features 100-Mbps token-passing network Single-mode (100 km), double-mode (2 km) CDDI transmits at 100 Mbps over about 100 m Dual-ring architecture for reliability Optical fiber advantages versus copper Security, reliability, and performance are enhanced because it does not emit electrical signals Much higher bandwidth than copper Used for corporate and carrier backbones

32 Summary LAN technologies include Ethernet, Token Ring, and FDDI Ethernet Most widely used Good balance between speed, cost, and ease of installation 10 Mbps to 1000 Mbps Token Ring Primarily used with IBM networks 4 Mbps to 16 Mbps FDDI Primarily used for corporate backbones Supports longer distances 100 Mbps